"After seeing this, you wouldn't eat that cheesecake if I told you not to," Mills quips.

The calculations involved are Herculean, says Patz, but "Randy has worked out the mathematics. I'm convinced of that."

Because the scanner would largely rely on existing hardware, "if someone like a General Electric were to get behind this, we could have a prototype in six months," Mills says.

Illustration by Tom White

Despite Mills's grand ambitions, he admits to being vexed by complexities in a genetic sequencer he envisions, and he dismisses dreams of immortality.

"Life is probably limited by arterial flow in the brain. Those vessels wear out. Maybe someone will find a way of drilling out and retubing them, but then they'll find something else. There's always a weak link."